Tuesday, February 9, 2016

Image copyrightAlamyImage captionThe presence of stalagmites and stalactites in caves beneath the Nullarbor show that the desert was wetter in the past

A network of hidden caves has helped reveal the lush rainforests that thrived in one of Australia's harshest deserts between three and five million years ago.

The iconic Nullarbor Plain is a vast expanse of desert straddling South and Western Australia, which receives less than 3cm of rain annually and is nearly entirely devoid of trees.

This inhospitable landscape is generally believed to have evolved in a linear fashion, becoming increasingly more arid in response to a cooling event in the southern hemisphere, which began around 14 million years ago.

But now, scientists at the University of Melbourne say a mysterious period of rapid warming, beginning five million years ago, dramatically altered the landscape of the Nullarbor Plain, bringing substantially more rain and allowing new plant life to flourish.

"Our study shows that the warming and associated increase in rainfall happened quite abruptly by geological standards, within about 100,000 years," said palaeoclimatologist Kale Sniderman, who led the research.

"This increase in rainfall coincided with an increase in ocean temperatures, which implies that it may have been a direct response to a globally warming climate."

Image captionThe Nullarbor is one of Australia's harshest deserts and receives less than 3cm of rain annually

It triggered a two-million-year period when the Nullarbor was up to four times wetter than it is today, and low-lying shrubs were replaced with eucalypt forests, banksias and other plants that are now restricted to the east coast of Australia, he said.

This period occurred at the beginning of the Pliocene Epoch (5.3 to 2.6 million years ago), which is the last time the Earth's climate was as warm as it's predicted to get 100 years from now. As such, this period is viewed as the best indicator we have for how our planet will respond to global warming.

Caves hold the clues

The Nullarbor Plain is one of the world's largest exposed limestone plateaus and is peppered with hundreds of caves, says Sniderman.

These caves contain bountiful collections of stalagmites and stalactites - cone shaped rock formations that build up layer by layer over thousands of years as water seeps through the bedrock and drips into the cave.

Due to the presence of these caves, Sniderman says "it was always obvious that the Nullarbor had been wetter in the past - but nobody knew when that period was".

One of the team, Prof Jon Woodhead, is an expert in rock dating and had already amassed a collection of stalagmites and stalactites from the Nullarbor caves.

Prof Woodhead had dated these samples to the Pliocene Epoch, but hadn't been able to obtain any environmental information to support evidence for a wetter climate. It was Sniderman who suggested they begin searching for traces of pollen trapped in the samples, which might have entered the cave with some dust through a surface opening.

Image copyrightProf Jon WoodheadImage captionPollen inside rock samples allowed the scientists to establish that a rapid period of warming allowed forests to thrive in the Nullarbor

"So, by trial and error, and quite a lot of tedious work, we found that a small proportion... did have pollen in them," he says.

The discovery allowed them to reconstruct the vegetative landscape of the Nullarbor and to establish a "new record of environmental climatic change which had previously been impossible to generate".

Their new record shows that, before the rapid warming, the Nullarbor already had a dry climate, as it was dominated by Australian plants that mainly grow in dry conditions.

The team's results, which provide new insight into the ancient evolution of Australia's arid interior - and arid ecosystems across the southern hemisphere - were published on Tuesday in the Proceedings of the National Academy of Sciences.

A 'mysterious reversal'

Prof Michael Archer, a vertebrate palaeontologist at the University of New South Wales who was not involved in the study, says recovered mammal fossils indicate that there were rainforests in Australia much further west than there are today.

He says the team has "demonstrated with very high precision" that there was a brief period when the southern hemisphere went through a rapid return to a greenhouse state.

"Some people have assumed it was a steady shift toward the ice ages, but the early Pliocene represents a mysterious reversal in this global movement. All of a sudden there was a moment when it was brilliant. The trees blossomed and spread, the possums smiled, and it was a wonderful time.

"But it just didn't last. And then, as quickly as it began, the world began to return to the long-term trend, headed for the ice ages," says Prof Archer.

"The most important takeaway message here... is that we're actually beginning to get a glimpse of what we may be headed for now," he says.

"Australia has profoundly changed, very rapidly in the past, and it's likely to do so again."

Keep these in mind as you contemplate the direction of the American government over the past 50 years and especially since the Obama election.

The Goals of Communism

(as read into the congressional record January 10, 1963, from "The Naked Communist" by Cleon Skousen)

1. U.S. acceptance of coexistence as the only alternative to atomic war.

2. U.S. willingness to capitulate in preference to engaging in atomic war.

3. Develop the illusion that total disarmament of the United States would be a demonstration of moral strength.

4. Permit free trade between all nations regardless of Communist affiliation and regardless of whether or not items could be used for war.

5. Extension of long-term loans to Russia and Soviet satellites.

6. Provide American aid to all nations regardless of Communist domination.

7. Grant recognition of Red China. Admission of Red China to the U.N.

8. Set up East and West Germany as separate states in spite of Khrushchev's promise in 1955 to settle the German question by free elections under supervision of the U.N.

9. Prolong the conferences to ban atomic tests because the United States has agreed to suspend tests as long as negotiations are in progress.

10. Allow all Soviet satellites individual representation in the U.N.

11. Promote the U.N. as the only hope for mankind. If its charter is rewritten, demand that it be set up as a one-world government with its own independent armed forces. (Some Communist leaders believe the world can be taken over as easily by the U.N. as by Moscow. Sometimes these two centers compete with each other as they are now doing in the Congo.)

12. Resist any attempt to outlaw the Communist Party.

13. Do away with all loyalty oaths.

14. Continue giving Russia access to the U.S. Patent Office.

15. Capture one or both of the political parties in the United States.

16. Use technical decisions of the courts to weaken basic American institutions by claiming their activities violate civil rights.

17. Get control of the schools. Use them as transmission belts for socialism and current Communist propaganda. Soften the curriculum. Get control of teachers' associations. Put the party line in textbooks.

18. Gain control of all student newspapers.

19. Use student riots to foment public protests against programs or organizations which are under Communist attack.

20. Infiltrate the press. Get control of book-review assignments, editorial writing, policymaking positions.

21. Gain control of key positions in radio, TV, and motion pictures.

22. Continue discrediting American culture by degrading all forms of artistic expression. An American Communist cell was told to "eliminate all good sculpture from parks and buildings, substitute shapeless, awkward and meaningless forms."

27. Infiltrate the churches and replace revealed religion with "social" religion. Discredit the Bible and emphasize the need for intellectual maturity which does not need a "religious crutch."

28. Eliminate prayer or any phase of religious expression in the schools on the ground that it violates the principle of "separation of church and state."

29. Discredit the American Constitution by calling it inadequate, old-fashioned, out of step with modern needs, a hindrance to cooperation between nations on a worldwide basis.

30. Discredit the American Founding Fathers. Present them as selfish aristocrats who had no concern for the "common man."

31. Belittle all forms of American culture and discourage the teaching of American history on the ground that it was only a minor part of the "big picture." Give more emphasis to Russian history since the Communists took over.

32. Support any socialist movement to give centralized control over any part of the culture--education, social agencies, welfare programs, mental health clinics, etc.

33. Eliminate all laws or procedures which interfere with the operation of the Communist apparatus.

34. Eliminate the House Committee on Un-American Activities.

35. Discredit and eventually dismantle the FBI.

36. Infiltrate and gain control of more unions.

37. Infiltrate and gain control of big business.

38. Transfer some of the powers of arrest from the police to social agencies. Treat all behavioral problems as psychiatric disorders which no one but psychiatrists can understand.

39. Dominate the psychiatric profession and use mental health laws as a means of gaining coercive control over those who oppose Communist goals.

40. Discredit the family as an institution. Encourage promiscuity and easy divorce.

41. Emphasize the need to raise children away from the negative influence of parents. Attribute prejudices, mental blocks and retarding of children to suppressive influence of parents.

42. Create the impression that violence and insurrection are legitimate aspects of the American tradition; that students and special-interest groups should rise up and use united force to solve economic, political or social problems.

43. Overthrow all colonial governments before native populations are ready for self-government.

44. Internationalize the Panama Canal.

45. Repeal the Connally reservation so the United States cannot prevent the World Court from seizing jurisdiction over nations and individuals alike.